Part A
74VHC14MX
Công ty bán dẫn Fairchild
- Lifecycle
- Active
- Stock
- 3753 PCS
- Package
- SOIC-14
- Series
- Logic - Gates and Inverters
Replacement verdict
Not a drop-in replacement
The 74VHC14MX and 74VHC00SJ are not functionally interchangeable. Although both devices share the same VHC logic family, supply voltage range, and SOIC-14 footprint, they implement fundamentally different logic functions: the 74VHC14MX provides six inverting Schmitt-trigger buffers, while the 74VHC00SJ provides four 2-input NAND gates. The differing gate function, channel count, and input threshold behavior prevent direct substitution without circuit redesign.
Different logic function
Different channel count
Different input threshold
Different pin function
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | 74VHC14MX | 74VHC00SJ | Why it matters |
|---|---|---|---|
| Logic Function | Hex Inverter with Schmitt Trigger Inputs | Quad 2-Input NAND Gate | The logic function determines the boolean operation performed; these parts are not functionally interchangeable. |
| Number of Circuits | 6 | 4 | The number of independent gate circuits affects how many signals can be processed in a single package. |
| Number of Inputs per Circuit | 1 | 2 | Input count per gate determines the logic capability and wiring requirements of each circuit. |
| Schmitt Trigger Input | Yes | No | Schmitt trigger inputs provide hysteresis for noise immunity and slow input signal conditioning, which the NAND gate lacks. |
| Output Type | Inverted (Active Low) | NAND (Active Low) | Output polarity and logic response differ, affecting circuit behavior and signal inversion requirements. |
| Supply Voltage Range | 2 V to 5.5 V | 2 V to 5.5 V | Both parts operate over the same VHC supply range, allowing use in similar low-voltage logic systems. |
| Propagation Delay (Typical) | 5.5 ns at 5 V | 5.5 ns at 5 V | Similar propagation delay means comparable switching speed in timing-sensitive applications. |
| Output Drive Current | ±8 mA | ±8 mA | Matching drive current indicates similar fan-out and load-driving capability. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Identical temperature ratings ensure both parts suit the same environmental conditions. |
| Package Type | SOIC-14 | SOIC-14 | Same package and pin count allow direct PCB footprint compatibility, though pin functions differ. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | 74VHC14MX | 74VHC00SJ |
|---|---|---|
| Supplier | - | onsemi |
| Series | 74VHC | 74VHC |
| Part Status | Active | Obsolete |
| Logic Type | Inverter | NAND Gate |
| Number of Circuits | 6 | 4 |
| Number of Inputs | 1 | 2 |
| Voltage - Supply | 2V ~ 5.5V | 2V ~ 5.5V |
| Current - Quiescent (Max) | 2 µA | 2 µA |
| Current - Output High Low | 8mA, 8mA | 8mA, 8mA |
| Logic Level - Low | 0.9V ~ 1.65V | 0.5V |
| Logic Level - High | 2.2V ~ 3.85V | 1.5V |
| Max Propagation Delay @ V Max CL | 10.6ns @ 5V, 50pF | 7.5ns @ 5V, 50pF |
| Operating Temperature | -40°C ~ 85°C | -40°C ~ 85°C |
| Mounting Type | Surface Mount | Surface Mount |
| Features | Schmitt Trigger | - |
Frequently asked questions
What are the primary functional differences between the 74VHC14MX and the 74VHC00SJ?
The 74VHC14MX is a hex Schmitt-trigger inverter, providing six independent inverter gates with hysteresis on the inputs. The 74VHC00SJ is a quad 2-input NAND gate, providing four independent NAND gates without Schmitt-trigger inputs. They differ in logic function, input threshold behavior, and gate count.
Are the 74VHC14MX and 74VHC00SJ pin-compatible in their respective packages?
No. The 74VHC14MX is typically supplied in a 14-pin SOIC package, while the 74VHC00SJ is typically supplied in a 14-pin SOIC package as well, but their pin functions differ because one is a hex inverter and the other is a quad 2-input NAND gate. Pin-to-pin compatibility is not guaranteed and must be verified against the specific manufacturer datasheets.
Can the 74VHC14MX be used as a direct replacement for the 74VHC00SJ in a logic circuit?
No. The 74VHC14MX performs inversion with Schmitt-trigger hysteresis, while the 74VHC00SJ performs 2-input NAND logic. They are not functionally equivalent, so a direct replacement would change the circuit’s logic behavior and is not recommended without redesign and validation.
Do both devices operate from the same recommended supply voltage range?
Yes. Both the 74VHC14MX and 74VHC00SJ are VHC-family CMOS logic devices and are specified for a recommended operating supply voltage range of 2.0 V to 5.5 V, per manufacturer datasheets.
Which device is better suited for slow or noisy input signals?
The 74VHC14MX is better suited for slow or noisy input signals because its Schmitt-trigger inputs provide hysteresis, improving noise immunity and clean switching on slowly changing waveforms. The 74VHC00SJ does not have Schmitt-trigger inputs and is intended for standard digital logic signals.
Are the 74VHC14MX and 74VHC00SJ available in the same package types?
They may overlap in some package offerings, but they are not guaranteed to be available in identical package types across all manufacturers. The 74VHC14MX is commonly offered in SOIC-14 and TSSOP-14, while the 74VHC00SJ is commonly offered in SOIC-14. Package availability must be confirmed with the specific manufacturer or distributor.
What is the typical propagation delay for each device?
Typical propagation delay depends on supply voltage, load capacitance, and manufacturer. For VHC-family devices at 5.0 V, typical propagation delays are in the low nanosecond range, but the exact values differ between the 74VHC14MX and 74VHC00SJ. Always consult the specific manufacturer datasheet for verified timing specifications.
Can both devices be used in mixed 3.3 V and 5 V logic systems?
Both devices are VHC-family CMOS parts with a 2.0 V to 5.5 V supply range, so they can operate in 3.3 V and 5 V systems. However, input voltage compatibility, output drive, and interfacing levels must be verified against the datasheet and the target system’s logic thresholds before use.